Renal Labs - Fiore Flashcards
what is included on a UA
Macroscopic and Microscopic evaluation
what are the macroscopic findings on a UA
Inspection for color, appearance, odor
measurement of pH, specific gravity, protein, glucose, RBCs, nitrites and WBC
what are the microscopic findings on a UA
analysis for casts, crystals, cells
what is the pathologic causes of cloudy urine
pyuria
lipiduria
what is the food or drug cause of cloudy urine
purine-rich foods
what is the pathologic cause of dark yellow urine
concentrated
what is the food or drug cause of dark yellow urine
carrots
what is the pathologic cause of orange urine
bile
what is the food or drug cause of orange urine
pyridium, phenothiazine
what is the pathologic cause of red urine
hematuria
hemoglobinuria
myoglobinuria
what is the food or drug cause of red urine
rifampin
beets, blackberries, rhubarb
what is the pathologic cuase of brown urine
bile
myoglobin
what is the food or drug cause of brown urine
fava beans
l-dopa, flagyl, nitrofuratoin
what is the pathologic cause of green/blue (purple bag syndrome) urine
multiple bacteria (indwelling catheter)
what is the food/drug cause of green/blue urine
amitriptyline, IV cimetidine
what is found on dipstick tests
Leukocytes (LEU)
Nitrate (NIT)
Urobilinogen (URO)
Protein (PRO)
pH (pH)
Blood (BLO)
Specific Gravity (SG)
Ketone (KET)
Bilirubin (BIL)
Glucose (GLU)
what correlates with urine osmolality
specific gravity
what is low specific gravity indicative of
possible acute kidney injury, diabetes insipidus, over-hydration (water)
what is high specific gravity indicative of
Dehydration, SIADH, Addisons’
what is the normal pH of urine
5.5 - 6.5
usually slightly acidic
what increases acidity of urine
proteins and acidic fruit
what increases alkaline urine
citrate foods
when is a urine glucose positive
serum glucose > 180 mg/dL
what is a by-product found in the urine of RBC breakdown
bilirubin
what is indicative of bilirubinuria
hepatic disease
choledocholithiasis
pancreatic obstruction
when does urine protein increase
diabetic nephropathy, pregnancy (eclampsia), severe exercise, cardiovascular pathology and medications
what is the normal albumin excretion
< 30mg/day
what is the screening test of choice for diabetic nephropathy
urine albumin to creatinine ratio
- requires a 24-hour collection
what should you obtain in high ketonuria
serum ketone level
what protein are we testing with a protein dipstick test
Albumin - less sensitive to other proteins
what does microscopic urinalysis detect
solid elements
-RBC, WBC, Epithelial cells, Fat, Casts, Bacteria, Fungi, Crystals, Spermatozoa
what is Pyruria defined as
> 5 WBC/HFP (high powered field)
what does squamous epithelial cells on urinalysis suggest
contamination
lining of end of urethra and contaminants from vagina
what are transitional cells
cells from lining of the bladder
usually normal finding
what is renal tubular cells on urinalysis suggest
pathology
can progress to oval fat bodies: Lipiduria
what are Casts
clyindirical structures composed of mucoprotein
from distal convoluted tubule or collecting duct of nephron
what are the different types of urinary casts
hyaline casts
waxy casts
RBC casts
WBC casts
epithelial casts
granular casts
*muddy brown casts
Fatty casts
mixed
what are hyaline casts
non specific:
mostly normal, low urine flow
what are waxy/broad casts
advanced/chronic renal disease
cellular casts that remain in the nephron before going towards the bladder
what are WBC casts
kidney inflammation or infection
-interstitial nephritis
-pyelonephritis
what are renal tubular epithelial casts
kidney injuyr
-ATN (acute tubular necrosis)
-glomerulonephritis
-nephrotic syndrome
-interstitial nephritis
what are granular casts
degeneration of epithelial casts
fine vs coarse
may be d/t intense exercise/dehydration in healthy individuals
end stage kidney disease (ESRD)
what is pathognomonic for acute tubular necrosis (ATN)
Muddy Brown casts
-sloughing of tubular cells
signs of ischemic or toxic injury to kidneys
what do high number of fatty casts suggest
nephrotic syndrome
what is the most common cause of kidney stones
calcium oxalate
what forms with calcium
oxalate - found in green leafy vegetables and other foods
what are coffin lid crystals
struvite crystals
what is the most common medium for urine culture
blood agar and MacConkey agar
is urine HcG qualitative or Quantitative
Qualitative
what is a better measurement than specific gravity
osmolality
what is Urine NAAT (nucleic acid amplification test)
1st catch vs clean catch (UTIs)
what makes up urea
Nitrogen + Carbon + hydrogen + oxygen
what does an increase BUN suggest
impaired renal function
normal level: 8-18mg/d:
what is creatinine excreted by
kidneys
what is the best measure of kidney function
marker of glomerular filtration rate (GFR)
what is the breakdown product of creatine phosphate
creatinine (Cr)
What is the normal BUN level
8-18mg/d
What is the normal Cr level
0.6 - 1.2 mg/dL
what is creatinine a indicator of
kidney function
what is the normal BUN: creatinine ratio
10:1
what does a BUN:Creatinine ratio of 20:1 suggest
pre-renal azotemia
-dehydration
-renal hypoperfusion
what does the BUN: Creatinine ratio of less then 20:1 suggest
intra-renal azotemia
-acute tubular necrosis
what does the BUN: Creatinine ratio help determine
the cause of Acute Kidney Injury (AKI) or kidney failure
what is the normal GFR
> 90 ml/min/1.73m^3
what is the GFR value that is indicative of dialysis
< than 15 eGFR
what can cystatin C be used to evalute
renal function
what is Renin stimulated by
reduced blood volume and renal blood flow
what inhibits renin
sodium and water retention
